Telling a seven-year old that Christmas is one week away will cause palpable anticipatory reward. Conversely, telling the same seven-year-old that it is three months until Christmas will not invoke any anticipatory reward—only frustration.
Dopamine Reward System
We first reported on the dopamine reward system in the 1980s, primarily through our research and work with cocaine and opioid addicts. Anticipatory, cue-evoked reward is the primary mechanism that drives preoccupation, addiction, craving and relapse among persons with addictive diseases. Hedonically-driven behavior is influenced by the presence of reward-associated cues through neurobiological processes involving the mesolimbic dopamine system in the midbrain. In this article, Fonzi, et al. (2017) have advanced our understanding by demonstrating that the intensity of the dopamine reward is correlated with the time differential between the cue-driven anticipation and the use of an intoxicant or addictive behavior.
For the dopamine system to accurately assign reward-related information to a particular cue, the dopamine system must be able to differentiate between cues that have never been experienced together in the same context. Specifically, cue-evoked dopamine release in the nucleus accumbens encodes the time differential. Cues that quickly precede reward elicit a greater dopamine response relative to a cue reward with a delayed wait time. The dopamine responses between both short- and long-wait cues were evident when these cues were never experienced together or within the same context. This is much like the algorithm involved in extinguishing the Pavlovian response by increasing the delay between the conditioned stimulus, the bell, and the reward, the food.
Why Does This Matter?
The relapse rate for addictive disease is over 50 percent in six months. Cue-driven triggers drive relapse in otherwise motivated persons. Without very serious commitment to recovery, as is the norm with other chronic conditions (diabetes, asthma, rheumatoid arthritis, obesity, COPD, heart disease…), relapse is expected. Programs that provide a minimum of two years of active continuing care, including monitoring, demonstrate significantly higher success at two-year follow up. Five years of monitoring and continuing care is the standard among physicians and airline pilots. A five-year follow up study (DuPont, Gold) revealed that nearly 90 percent had not failed a single drug test, and nearly all were gainfully employed in their profession.
Unfortunately, short-term treatments have become the focus of care from overdose reversal to detoxification. Drugs change the brain, and they leave the person changed as well. Abstinence is often followed by long periods of emotional dysregulation plus issues with sleep, appetite, relationships and other problems that the former addict begins to think might be “cured” by taking just a little bit of drugs again. Given the current epidemic and high relapse and mortality rate, continuing care is essential if we are to stem the tide of addiction in our land.